And a far more controversial question: would it be allowed? Or would a successful European world-dominating quasi-monopoly on the FAANG scale get banned from the US market? We've seen twitches in that direction (remember the "Tiktok will be forced to sell to Oracle" nonsense?). Or in the aerospace market, things like https://www.theguardian.com/business/2018/jan/26/bombardier-... or https://www.bbc.co.uk/news/world-europe-32542140 ; Boeing vs Airbus shenanigans go back a long way.
I found out the other day that one of the UK's longstanding tech companies collapsed after accidentally buying a CIA front organization for illegal arms sales: https://en.wikipedia.org/wiki/Ferranti#Collapse
Or ARM: are they an "EU" tech success any more? As their ownership is passed from Japanese Softbank to US NVIDIA.